Generally, for an application (App) installed on a smart mobile phone, an icon of the application is added to the desktop of the smart mobile phone. Sometimes a badge can be added to the icon to indicate that there are unread messages in the application. Conventionally, the operation system of a smart mobile phone monitors unread messages of system applications, and obtain the number of unread messages for each system application. The operation system then uses the number of unread messages as a badge value of the system application, and adds the badge value to the icon of the system application.